SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8305340f6b9db08b37b3f546ef6d13a0656a3a87a432ae7949ec317e5a342365' 
  AND token = 'FH6TaJNQNxIHDgMaWxk8qaTzYNbAIuCEUJJ1OTPx1Gg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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