SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3d5732158653675630ecd6fcf8d6449d7c44d0392464d1f1928c1b5c81d5ecfc' 
  AND token = 'Zr41tpagxz/oDRFqhuGQtM+hzIuqavsqnPaPezInACg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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