SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6071a349dd18abd5cc2ea19be73780be690feed2f6ddb9c60c9d17a5d3bc6290' 
  AND token = 'ao5SVVVLqUaWdGHY0DYSmWVn57HR9jkVeKBSNdHIMEc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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