SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9487e7488c65491b85b39eb73de92215db0c9e39f06c906facdd809844d6f776' 
  AND token = '4TprQj+yLTKDdGjpf2ydHF4AXW0JtlENi0kdU4xtRLA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}