SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a74ed63113f6107cf3109bd11b568734c5ef6d0e83341a6d30497bbb9a753af2' 
  AND token = 'fqyFiwEB+qDAtnVMDALb268sVOanqMFHIfgeYJIMAhk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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