SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e1ac830c61aceabb13eb9867ed6211e818d7ac44ad9121d84300eb5390bc0b3c' 
  AND token = 'jattdVO0PO50yDVyAQe93ULU4NcrUYLmZ3KA8Ofskvo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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