SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b5160b27d45fb791af6f396b4756852760ca21e902b5b4cf5147dcefd5f1036a' 
  AND token = '8j5AVMk7ONAsGKRrYwqLWgp4/2Flksjyp0KesP+mo/w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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