SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6af5b46c45290d9a726ae32e0c4506bcbb0e51b5d26a7392bb804a7b4041a69c' 
  AND token = 'KjIqUwFqQmCsQwUIXuVQH1cUaS9A2/HI+IlmEebk27E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00135

JSON explain

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