SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6777c293f9e372c3137fb4601be45ceaeaf0b8c1b44f48cd28f0c640e51ae190' 
  AND token = 'RdeD3XR9UijDXQ67nYSNURXwKVxtSqi7g5TzHWedkHU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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