SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3b16c421c98ac85d96aacdb8bd93ef3be281754fb4312da66ba5232032eeba1c' 
  AND token = 'wDpTfK/VeeFEUkyVRWa5hsCDmhuqg3vKkUCy5TJqa6U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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