SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cb590d27bb4aab750b0498922cfe442e232644d09d748d66e6e2faa4e2e80101' 
  AND token = 'yKSaD9BXPNKdfw/D5WuzDRd793MAv1/5A2aYYIOGnwg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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