SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '50bb85321c53107c6183b461b509bfbd50b5ebe28acfbf3f2bfcddd5494cc765' 
  AND token = 'ATQYRwLPLygM9TJsSCQ3SniKjGZM9TR7ZKcuKD4hjMU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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