SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'b111b088da92df646bc0960318763f00d3325a3fbb51e525bb08e9e2dee2741a' 
  AND token = 'MoWIaPCLhxpnhgX7no9bYuez3gO6CEAonWMR7llN/Nc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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