SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '40099fdf9123da9012b16ea68da9e53eccfcda81ef1a76096aa04d8e49adc42e' 
  AND token = 'QOXNUeuCI9eQy4/qFFBOrEU39enZGYcmeQaqveFFWa4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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