SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f1c16fbf28730230944511f6f4071940d161d0fba77fdcfc692ed027a3105f07' 
  AND token = 'j9NQKN+b9vGvZRvG73oe+nGqqoaagmgHY0A99byCgIM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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