SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5ab6efe01fdd6816e8363be4fb32d70e538e84b144c12c18350885fa85bb3438' 
  AND token = 'WYXcFqmDVQLfF+G6ZTJhHFPDiUSfUOhaPk/MqdxV8UQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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