SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bccb0bbd0b8700b75f00bb7d5b917ea569fca4b6c38724d14a6d73ad01307cb2' 
  AND token = 'zOvsGMfUrIpp0dU7vx3oPHgPQjwr0is9bZKPsQSa+EQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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