SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a336d927c3323b17c9d8f2944e2e45d4c88613d388ac7ebad3b44a71101245c0' 
  AND token = '9s++Px7Nbq/wGd7cy76firLpgUuRWYwXjpGYl0mRjkg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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