SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '91883128adde71956917cf9d39ceafe2ea39e7b2263cdbfebdfb0aa196a8463f' 
  AND token = 'u72qLk7DIhmqXzp+29STA4C1zc3YMGgTFh1uxnELHqc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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