SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bcc78381271a20ca0c92c9938fcad8badcccf4a01ee1701ccdde20d96c6084e4' 
  AND token = 'oHySy2Skf/VJymd4gEDZEL8JXGmW+34CYUQafEEIWi4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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