SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '03207622f726213bffee5d5bc7229e3ab822a44de91e1ba25d0268b2948a6165' 
  AND token = 'QK6YMZGFJBrBNTIVdvlaKKgH7DOUC+fPDSbXKEYhzHw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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