SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f0c7d53d4287a339fd94306c478dde871b9487164536fa5a454968f8b217ddd5' 
  AND token = 'hBBOfAexM4ySHmq+WRV9E+rQgkZBqQmPhYsr02qN/Q4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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