SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4a63c6b97d35adca1b16d632e2ae850f57d600e54087a1fc2f8b7a6c0b013bf3' 
  AND token = 'X3r8M1kkZzojvO4u8bXRu5rd/me417o6fnDUVuhYc8Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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