SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3091210c1b7cc470467459748393cfbb9aa5b526f0fd10095c0e6172df3780f7' 
  AND token = '6OMDDCW1VzEDm6lotjWQUh9FsH6jwMZBVbuqd4Vd8pM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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