SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '4be53e23c9657d0244f2f393ca3cabcbaedd02211f8bfef2aee6edeb4d3f1e10' 
  AND token = 'FICzh9hAhLGz+Jh/U29TwNL0+JbXWltYFimEqm6Er5o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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