SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f3608ff0daff5df1a1f729301a4ca63f6fdf0ec724388c3a6463be80a475a695' 
  AND token = 'CSzm7qKvvoYgZ1/EPpdQGORlnCjS6xJ3DNHlf5QOOZQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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