SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '963f83b106bb4917cda90987f586768df81ee65a979a1ba19990bb79cfa2fad0' 
  AND token = 'rLddj/p7heKQjJVsgjRwNR+/5QrMvdXB3xyGFl0l3Fo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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