SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '13b182941fdfbf98a318faa6a23ff696f68d4736bd924d335de903634a724eee' 
  AND token = 'rz6Kcti8H5FBoIdYlfTv4AH2xSVIACVgeAHQWURTXgY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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