SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '192717e6ec696ccf9438152ba91625e6bce497fe0918d3a1d9123a1734761cc9' 
  AND token = 'l1NZxFam2Y39VYLTn+3LQlmm5TnCBov61C3icy7Dodk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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