SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a93c1273d264a7992c986adcffcb41f951f7cc5d95502840f819f65390fe0823' 
  AND token = '04VE/ayKNT7NsidYR8qmFXocCzahEzlOzOKLmKF2ytQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}