SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c52c44d2e91b0ffb143f006ad6f43e4b9693ab3f260a57e0e724dc7503972fe4' 
  AND token = 'hDSxxw3SqekmbtRPLTF2kDYFcgAWRfHQRvkHMfhy80I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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