SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '557c8460052ce35b6020abed78bedbe903ecea630f95603454f03a7e0b9eacf1' 
  AND token = 'IeVIwb2fWVnz1R/8VOuew0QqxX436tczY0UBTKV+8jc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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