SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ce3a3dbefc4caf6d8f59969b927988a3f2f80525e690529bcdcbd155e5c38784' 
  AND token = 'WlDc6cgr8ZjLtSxSydJGvtLxzeeMCR6ltV3pvQD3bNA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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