SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'df06c1a39f89bf7755760b854e5f9c9c4fb500b9ccdb04a2c16bf35e4b302fb2' 
  AND token = '93dm4229jHCKkyacz9pj+vt0+t0QNH7q7UAuBvbVsqg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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