SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c6df75a023ca7bd4e354587d9cde7cca0fce32c75b15c58a39cc48cec177ab33' 
  AND token = 'Vp3Kj3z4L+pmhKqwLKtH7hZAutvZYxQHE1+HLGU4GFg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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