SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9654cb2eec4c44621d420dc36774758c2a2c060ac2f04afa5840ca7ae10ed589' 
  AND token = '+yR7gzcTcfEyseimd1hYda7WiU7LTZcfGFvtG5GSTa8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}