SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5be26eeedb3bf3555d4a1848105d35a2c89daa9fb6a08eadb647f4299d5acb44' 
  AND token = 'gnLfT71UiaIKV8N87WMW5v3ykyUCpCrDCc5UmUsE2mw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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