SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e4b8a5d874ed064c45b27dd2eb6c45a04b4ed186f2baec8a598b1f8eebb867b9' 
  AND token = 'TTUznKFENT/0jlddhXa47QqGxajWroNWz7vRRMZzrXw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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