SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2684a6e1a397993cf76a62bfbe26c01e2e043fba4c791a27219baa11c443cbca' 
  AND token = 'UI4WkuDibdZ/ZyucrFkFHcKyzBRRC3K43vETzUHbbno=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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