SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6577530da6d31b80fb41852cb8c451da000f9cad5ce09d8896528976787582e1' 
  AND token = 'CTC3NkBBWUoyqDwyVZBIEZH3OwXZ7KpYkvhUuvEL2Qc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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