SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0fbb1d3153f21c54ead28813f91726e30eaab48d0bc7dc73924336e48d2d4441' 
  AND token = 'A5y+tGjRCEvBp4ChNzQtZjmuwMHy0TwIVKy+kxwkGqw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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