SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '82b51218f7db378ccd36a4f6594f221deecffaa7f51f06fba7fbee04514fa78b' 
  AND token = 'EKoZmtU8yr3C6DSE+ZWOwawr4/KCKcZCx9jqY6W0luw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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