SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '31d5742d946b92eb6344e8c4308c9d797c5bb3dcf6f855d1f35b6968765912da' 
  AND token = 's6Jt8lg4rN/+i1QHRuIm2V3KLP8GfCQdrO1a7m5cUEU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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