SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2c1cd07f610562403558dffb8f5604343900be1740f16b65dc4913c286fdd187' 
  AND token = 'DHzOZUC+KqColSTbz7DSyb85peDHBccNjA4+gvJHZEk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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