SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '150807d898202ac334b256591b6052622419403888fa364a5689e655e40dddcb' 
  AND token = 'p/Nr/xf7JqKT6sISlSIRXUQOvtHfcUJ9GiNoPJCGHUA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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