SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f1415e022dff75bf344c9a5adc3ddb53b8ea5cc2ebd90fe055b891db476fb91d' 
  AND token = 'MK0GahANGyyJ8I1oEzM4lakmEdCvdc9SfxaylHYE4QA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}