SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '458f85d859e2121b947203993b5ef82211c68096e277dfd6fbf714de971b496e' 
  AND token = 'mCQDRXRPiS+cOMU4LDjmIIP1KoTa+UINhHdlz4JLBi0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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