SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e6ffe26a4ed7a9bdca34e6b8748712873edc7fa056fc07f1f1b1e38a9189bf5d' 
  AND token = 'Q5YQlvTn2PgzInhqY5xjpWJ+usL+AwitYiuaHuIA/9c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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