SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '9e5a3ee2ae736061ca421fe1e78756a2e288400b35411b29b6482fd41b2913dc' 
  AND token = '2smBt/aqlUQSaqsapLsdrFpczgu2zbw3vWfkvMkVZeg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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