SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd8b31664d7a272e746ca7ef4393acd0037820635da1808526eb6d7762712d128' 
  AND token = 'Z7iBbNTPfUeb6EGxaPOV+1jH2UN/6dm3albNIDz38zA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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