SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'edc8444a6d521fd7e61b8430661ecb98cb72491831863a4c8a270f7eab8ccadc' 
  AND token = 'M1rej/KrVHUDStOzY4YKgE1KowjqgmFyuZxpLuSgtyE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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