SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '79622fe3fe31e8638c4c244339cdfbfe276afe08cbbd24f30918b33828890245' 
  AND token = 'qIaf9R3j8wz/ZQ1OXaYjlvzbvS7osZyJ84KTORFgZNc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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