SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4c22c54df9e173ccd96dec19d27df136a0938d5ed3153441f5b69c380553c9ff' 
  AND token = 'LdD7PZ00uoWmsrpwdHi5qzHbKzsGszyaJVYUytK2FGg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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