SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '9ac40df6b1a1a56b3c9c09c2f296b577a5c53e2f5dac694abf7e13d3d7fa5e36' 
  AND token = 'zNDYjLqlOILsdDQbDxCKygbmb0XE+8g57Hh9qG08FEg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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