SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4bb0f9eb2105f7322ed7c22fb00d534eb35091cc39a304f2f9ae490947b91544' 
  AND token = 'ewIatDN+YiMdr98aAmeI5ieXOo5R+1GKiHbnbBSK/kw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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