SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7103dc485f4013a8d0fb2f9d014c3d1474775b2ed0552b174a7adda98f2342b5' 
  AND token = 'nuFGEaUq8mJ155Vo/gzJMw33WpYQKQcMUo/IYZQzpD0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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