SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a61fd805a37437cbe304d7c884121c947f9ada9c0c9acb88530606c8c7dabdd1' 
  AND token = '0M7q48oqSbn8wQv860Lnm7ykgWhMR0rnQjvRZcPVAq4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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