SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7ae345865eda4c72defeaeaea39c9582ae5368954c6b8c35122b17cc4c71736c' 
  AND token = '22gqRZKAw1wOiuSVBVTQaAFJRS+htJhrjSlpNSM+B58=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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