SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fa32965c013d4e288d6d9aeeeea63d8d42226d64be4f6df69cc6fdbb9ccb09f8' 
  AND token = 'fu+k0GNjKXqwV9u1h7/RuBSJ2dwqaMFgX/vrHYVMKLU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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