SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '802271bf4bf5aad5c76de17618b32ada32a4050bce3db86d65bf136872df32b2' 
  AND token = 'JEeJLqYlZGBQ7T13nSWB8gPG1DwU235EGfWaEcQAXjs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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