SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0d5d0959332b20daaf6f72eee5fe1d62f88e05804f58ddc854f1fa584383d84e' 
  AND token = 'r/sBAxJe2QpISQ3xiYoWlBHesq4p86nNvuhUmZsjtks=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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