SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cb38d0a021b61e7106bfeb020e651bd165dc35eb750013320691ea7bd7549207' 
  AND token = 'VI1lxxyc94XCevQkSQvOYZi+pJZvU/4Z5q3rgk2sG+k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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