SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e18ffd5ca55dc21d8c7b4646622dffc305a33d5c130c709d584affa1cfc4fb9c' 
  AND token = 'cQvNWMVXpjezCxoMJmsIQ/cEUNQvyHkBEYTqwjz4a+c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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