SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '97314ff777e7362c1b676a8d06b6d6771aa51ceb7acd08e79fa334cc0a80af34' 
  AND token = 'bavUOkvXaubp+V1y2iUldbjEJMhkKjW4rRhbcnkpsps=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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