SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6300fa49225ad2674735255ff9b4cd4cc917d24db70e4d425cca698b06b951c8' 
  AND token = 'wCiMlPLnZZ+fin8CroObfHk8lsX7p+QYGClfpxu4IG4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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