SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f880116d3258984929e2ead955b1b65b0ab56eca2df1592c168b0abaa5446cda' 
  AND token = 'nQxleYTGjv5oLbDVXzeO64YHPd+HIbo7hzlQsMHJbCo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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